Is Ther a program that can handle automatically billing every month?, most of my customer pay a fixed amount for 10 months, I use QB Memorized Transactions But I have to go trought every invoice to change the subjec.
Payment 1 out of 10, Payment 2 out of 10 and so on.

Simple solution: Instead of calling them 1-10 of 10, just call them the Monthly Installment for Lawn Maintenance Services. Then you don't have to edit each one, each month. The contract your customer signed should out line the payment terms, so the customer knows they are paying March - December, or whatever it is. No need to also clarify that again on the invoice.